Field of the Invention
The present invention relates to wireless communications, and more specifically, to a method and apparatus for acquiring information using a device in an idle state in a wireless communication system.
Related Art
With the recent trend of increasing high-rate data traffic, fifth generation mobile communication technologies are in discussion for their realistic and efficient backup. One of requirements for fifth generation mobile communication technologies is the interworking between heterogeneous wireless communication systems, particularly between a cellular system and a wireless LAN (WLAN) system. The cellular system may be one of a 3rd generation partnership project (3GPP) long-term evolution (LTE) system, a 3GPP LTE-A (advanced) system, and an institute of electrical and electronics engineers (IEEE) 802.16 (WiMax, WiBro) system. The WLAN system may be an IEEE 802.11 (Wi-Fi) system. In particular, WLAN is a wireless communication system that is commonly used for various user equipments, and thus, the cellular-WLAN interoperation is a high-priority convergence technique. Offloading by the cellular-WLAN interoperation may increase the coverage and capacity of the cellular system.
The arrival of the ubiquitous environment led to a sharp increase in demand for seamless services anytime, anywhere. The fifth generation mobile communication system may adopt a plurality of radio access technologies (RATs) for always gaining easy access and maintaining efficient performance in any place. In other words, the fifth-generation mobile communication system may use multiple RATs in a converging manner through the interoperation between heterogeneous wireless communication systems. Each entity in the plurality of RATs constituting a fifth-generation mobile communication system may exchange information therebetween, and accordingly, the optimal communication system may be provided to a user in the fifth-generation mobile communication system. Among the plurality of RATs constituting the fifth-generation mobile communication system, a specific RAT may operate as a primary RAT system, and another specific RAT may operate as a secondary RAT system. That is, the primary RAT system may mainly play a role to provide a communication system to a user in the fifth-generation mobile communication system, while the secondary RAT system may assist the primary RAT system. In general, a 3GPP LTE(-A) or IEEE 802.16 cellular system with relatively broad coverage may be a primary RAT system, and a Wi-Fi system with relatively narrower coverage may be a secondary RAT system.
In a fifth-generation mobile communication system constituted of a plurality of RATs, a primary RAT system needs to grasp the entities of a secondary RAT system that operates within its own coverage. For example, in case that a primary RAT system is a cellular system, and a secondary RAT system is a Wi-Fi system, a cellular node such as an eNodeB (eNB), mobility management entity (MME), or new cellular entity need be aware of which access points (APs) are in operation within its coverage. An entity of a secondary RAT system should report information on itself to a management device (for example, management server) existing in the secondary RAT system. In this case, the entity of the secondary RAT system may acquire information on the primary RAT system through the connection of the secondary RAT system with a general device, and may report information on itself to the management device based on the acquired information on the primary RAT system through a wire network of the secondary RAT system.
When the entity of the secondary RAT system acquires information on the primary RAT system using a general device, there is a need for a method to reduce overhead of the entity of the secondary RAT system and the general device and to efficiently acquire information on the primary RAT system.